The bullet went through the child's leg and narrowly missed a main artery. He remains hospitalized.
[Ads /]
The family drove the boy to St. Christopher's Hospital for Children where doctors worked on him just before 1 a.m. Thursday, according to investigators.
Police say the boy found a gun inside the home and fired it. How it happened is unclear.
A source close to the investigation says the parents of the boy are giving conflicting stories, and the shooting scene had been cleaned up when police arrived.
"It's a matter of who was in the house. Apparently the gun was not there when police got there," said Joanne Pescatore, the supervisor of the Philadelphia District Attorney's Office's Homicide and Non-Fatal Shooting Unit.
Pescatore says the boy's father, Rafael Ramon, is a person of interest.
[Ads /]
"The father has many priors which makes him ineligible to have a firearm. And the firearm was obviously alone in a room with a 5-year-old," she said. "So maybe not just him but other adults that were present may be facing charges."
The shooting comes in the wake of another accidental shooting in Allentown earlier this week when an 11-year-old boy was shot and killed by his younger brother.
No charges are expected to be filed in that shooting.
The shootings once again shine a spotlight on the need for people to safely store and lock their guns.
Philadelphia Sherriff Rochelle Bilal and her office have given out 3,000 free gun locks this year.
[Ads /]
While most gun owners are responsible with their firearms, she wants even criminals and felons to get gun locks because it could be their loved one who accidentally gets shot.
"Lock the gun up. Come here and get it. We're not going to lock you up. We don't know what you're getting a gun for, just come get the lock," said Sheriff Bilal.
If you want a gun lock, you can get one for free at the Sheriff's office at 100 South Broad Street in Center City.
RELATED: Check the 6abc Neighborhood Safety Tracker